WASHINGTON -- After making two appearances this season, veteran right-handed reliever Will Harris was placed on the 10-Day injured list by the Nationals on Friday with a strained right groin. The transaction was made retroactive to Wednesday.

The Nats made bolstering their bullpen a priority when they inked Harris to a three-year contract this past offseason. He was coming off a 2019 season in which he led all American League relievers with a 1.50 ERA as a member of the Astros. Harris was sidelined during Spring Training by an abdominal injury, and he made his debut with his new team on Sunday during the third game of the season.

In his two outings with Washington, Harris has allowed three runs (one earned), three hits, two walks and two strikeouts in 1 1/3 innings. On Thursday, manager Dave Martinez was optimistic the nine-year veteran would be able to recover during the four days the Nationals have off in between games because their weekend series in Miami was postponed.

“Harris has a little bit of a groin thing going on that we’re trying to take care of,” Martinez said Thursday following the Nats' win over the Blue Jays. “We’re hoping that [during] these days [off], we can nip it in the bud and get him ready for Tuesday.”

A new late-inning candidate to pitch along with Sean Doolittle and Daniel Hudson already has emerged early in the 2020 season -- fellow right-hander Tanner Rainey. The third-year reliever tossed four scoreless outings before allowing his first hit and run of the year (a homer to Teoscar Hernández) on Thursday. He has a 1.93 ERA over 4 2/3 frames with six strikeouts, two walks, one hit and one earned run.

“Since we got him last year, he’s matured a lot,” Martinez said. “The biggest thing with Rainey -- he’s got unbelievable stuff -- was his ability to throw strikes when he needed to. He’s done that. He proved that he could do that. He’s worked on throwing another pitch, which he hasn’t thrown, yet but I’d like to see him use it more, because it’s pretty effective, which is a changeup. … I think he deserves a chance to pitch in the back end of the bullpen, so we’re going to use him like that.”

The Nationals bullpen began the season shorthanded without southpaw Roenis Elías and right-hander Wander Suero. Elías was placed on the 60-day IL on Sunday because of a left elbow flexor strain, and Suero is continuing to ramp up at the alternate training site in Fredericksburg, Va. Both players were delayed in being cleared for summer camp workouts.

“Suero is doing fine,” Martinez said Thursday. “We’ve just got to build him up. Just like all these pitchers, what we’re starting to see is his velo’s kind of down a little bit. So we’ve just got to try to build him up and get him ready. But we’ll see. He threw the ball well the other day. He was still at 88, 89 [mph], but threw the ball really well.”

The Nationals were off on Friday, and players were encouraged to catch up on rest. They will hold intrasquad scrimmages on Saturday and Sunday, and bullpen arms can stay warm by pitching against their teammates.